According to Prestadir, the medallion you found says something about a Hunter King and the Mournshaws.
'Some of our kinsmen have gone on to the Mournshaws to scout the way. Perhaps you should bring this sigil to Daervunn at Echad Daervunn...perhaps he has come upon some knowledge of this Hunter King.
'Echad Daervunn lies far to the south of here in the northern reaches of the Mournshaws.'
Daervunn is at Echad Daervunn in the Mournshaws, far to the south of Echad Idhrenfair.
Prestadir suggested you take the sigil you found to Daervunn in the Mournshaws.